Automatic fire and burglar alarm



A. KOHLNDORFER AUTOMATIC FIRE AND BURGLAR. ALARM Dec. 11, 1934.

Filed June 16, 1933 Mama Patented Dec. 11, 1934 UNITED TATE P T NT OFFicE AUTOMATIC SAND BURGLAR ALARM AntonKohln'dorfer, MieSbach/Oberbayern, Germany .Applicationlune-lfi, 1933, Serial No. 676,102 .In Germany May 6,1932 I Claims. (Cl. 116-106) -'Ihe present-invention relates to an automatic instance, to the lever 3 there may be attached a fireialarmthe main advantage of which, in concord 3 (indicated by dotted lines in Fig. 1) which -trast -tofire alarms of known type, resides in the holds the lever in the horizontal position, sad

fact-that-it does not require any special knowlthread being stretched across the room to be 5 edge-on thepartof theuser. The fire alarm can protected, so that when the thread is burnt 5 be fitted by an'amateur at a suitable placewiththrough .or broken at any spot, the alarm signal out its being necessary to arrange. any electric is released; I switch or' the like. The cost of production is-very In this case the fire alarm is at the same time small. a burglar alarm. For the same purpose the The firealarrn consists of a mechanical-'acousframe 5 carrying the easily fusible mass may 10 tic signal mechanism with a setting device which also be carried by one arm of I a'rocking lever 6 -is adapted to be hel din the set pos.tion by means to the other arm of which there is attached a of an easily fusible or. easily combustible subcordor the like 7, which'is stretched across the stance (for instance, wax, a combustible cord or room'in question. The double-lever 6 is adjusted the like). In this arrangement the signal-release in a condition of equilibrium. If unauthorized in member rests on the easily fusible substance. The persons enter the roomand the cord is slightly bearing surface .of the release member can be moved, lever 6 and frame 5 will sW ng around widened. Thesignalling mechanism is contained their pivot 8 thereby releasing'lever 3 and in turn in a housing, from which the release member .prothe signalling mechanism. 1

"2'0 itrudes, and the easily fusible substance is dis- In the form of construction shown in Fig. 2, the

posed outside on thehousing. The said substance 'container 5' holding the fusible mass 4 is integral carried by a detachable frame, socket or the with the lever 6 which pivots about a pin 8, so that like. when the cord 7 is pulled it swings with this lever A burglaralarm maybe combined wLth the fire and releases the lever 3.

g5 'alarm. With thisobject in view the easily fusible, .According to Fig. 3, the bearing surface of the exposed substance engages with a tensionedband, ile'vers3 -is.pr0vided' with a broadened portion to thread or the like. 'Ihebandor thread may also prevent it from sinking too easily into the easily engage .ona'rioeking'lever carrying the substance fusible mass'an'd releasingthe. clockwork mechin an exposed manner. anism. Measures should be taken to prevent the The attached drawing shows three typical fire alarm from being set in operation uninten- 30 forms of construction of the fire alarm accord ng tionally in consequence of high external temperato the invention, Fig. 1 showing the first form ture. The pan 5 carrying the fusible mass 4 is, in elevation and Figs. 2 and 3 showing two modiaccording to Fig. 3, suspended on a lever 9 and fications of the alarm control mechanism. held in fixed position by a hook 10. As soon as According to Fig. l, in a housing 1 there is the hook 10 is released by a pull on the cord '7 or 35 accommodated a clockwork mechanism of known by pressure on its upward prolongation 11, the type which by means of a striker is adapted to lever 9 together with the pan 5, falls and releases actuate a bell 2. The wound-up clockwork is the lever 3, which is loaded by a spring 12 and a held in the locked position by a lever 3 projecting sliding weight 13, so that the bell rings.

40 outside the housing. This lever, under the in- If it is intended that the apparatus according 40 flu c f a p g 0 a W h tends o win to Fig. 3 shall answer to heat and fire, the pivoting downwards in the direction indicated by the ararm 10, 11 is put out of operation by tying it back, row and thereby to release the clockwork. It whereby the lower hooked end of the arm 10 does rests, however, on an easily fusible substance 4, not engage with the pan 5. Then the safety cord which is carried by a pan. is fixed in a hole 23 provided for this purpose at As the easily fusible substance there may be the upper end of the pan 5, this cord is drawn, for used paraffin or other wax, resin, artificial resin, instance, through an opening 24 of a pivoted arm but also easily fusible metals or alloys. If, in 21, and then the cord is stretched across the room consequence of an outbreak of fire, the temperato be protected in such manner that the pan is ture of the room in question rises, the easily raised, and thus the apparatus is in the set posi- 50 fusible mass 4 melts, the lever 3 no longer meets tion. Now if the cord is burnt through at any with resistance and falls thus releasing the clockplace the tension ceases, the pan which is conwork mechanism. The bell 2 then rings. nected to the lever 9 sinks and the apparatus Instead of easily fusible substances, easily comcomes into operation. If again a high temperabustible substances may also be used. Thus, for ture occurs in the room protected in this manner 50 without flames being formed, the signal release lever 3 sinks into the fusible mass 4 which has "become soft and releases the alarm mechanism.

' tion isbased.

It is evident that the cost of production of the device. according to the invention is extraordinarily low, and that the device can be manipulated by any non-expert. As the easily fusible mass is contained in special pans or frames it is impossible for the mass to become distorted under the influence of a high natural external temperature which, however, is not capable of causing the mass to melt. The apparatus comes into operation only when fire has actually broken out, or when there is immediate danger of fire (overheating of a story of a house). The pans containing the fusible mass 4 can easily be exchanged by a non-expert.

On the housing 1 terminal contacts or contacts of other type 14 (Fig. 1) can be fitted which are conductively interconnected by the falling lever 3. Thus it is possible to set a remote bell mechanism or a visual'signal-in operation.

Further, a device may be provided which indicates whether the apparatus is set or whether the clockwork mechanism is Wound up or not. With this object in view, in the form of construction shown in Fig. 3 there is mounted on the housing 1 a lever 16 provided with a signal disc 15 which at the same time serves as a loading weight. To the free end 17 of this lever is secured a cord 20 wound on a small drum 18 of the clockwork shaft. When the clockwork is wound up the cord 20 is wound up and the lever 16 moves into an approximately vertical position, in which the signal 15 is visible. When the clockwork is run down the cord 20 is unwound and the lever 16 falls under itsown weight. It is obvious that the arrangement can also be such that the signal disc 15 is visible only when the clockwork has run down and-is covered when the clockwork is wound up.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that What I claim is:

1. Alarm device comprising .a signal mechanism, a lever, heat responsive meansmarried by the latter, a flexible element retaining said lever and the means carried thereby in a condition of unstable equilibrium, and detent means normally supported by the heat responsive means in position to prevent operation of the signal mechanism.

2. Alarm device comprising a signal mechanism, a lever, heat responsive means carried by the lever, a flexible element retaining said lever and the means carried thereby in a condition of unstable? equilibrium, and detent means normallyflsupported by the heat responsive means in position to prevent operation of the signal mechanism, said heat responsive means comprising a pan containing a fusible mass.

3. Alarm device'comprising a signal mechanism, a lever, heat responsive means carried by the latter, a flexible element retaining said lever and the means carried thereby in a condition of unstable equilibrium, and detent means normally supported by the heat responsive means in position to prevent operation of the signal .mechanism, said heat responsive means comprising a pan containing a fusible mass, said flexible element comprising a cord, stretched across the room to be protected.

4. Alarm device comprising a signal mechanism, a lever, heat responsive means carried by the lever, a flexible element retaining said lever and the means carried thereby in a condition of unstable equilibrium, and detent means normally supported by the heat responsive means in position to prevent operation of the signal mechanism, said heat responsive means comprising a pan containing a fusible mass, said flexible element comprising a combustible cord, stretched across the room to be protected.

5. Alarm device comprising a signal mecha- 

